FIG. 9.

p300 does not acetylate Zac. Acetylation assay. GST-p300-HAT (25 nM) was incubated with GST fusions of Zac, Zac zinc fingers, or the general transcription factors TFIIF or TFIIE (1 μM each). Reaction mixtures were fractionated on a 10% SDS-polyacrylamide gel. A representative autoradiogram following 2,5-diphenyloxazol treatment and exposure for 2 days is shown. Open arrows indicate predicted positions of Zac and zinc fingers; filled arrows mark positions of acetylated TFIIF, TFIIE, and autoacetylated p300-HAT.